Investigation Of Eye Diseases

Special equipment is required for a more detailed ophthalmological examination and assessment. The eye examination can be done with commonly available equipment initially, this also includes an ophthalmoscope. History The history provides clues to the location, the onset and duration of symptoms as well as previous ocular discomfort, pain and pain character, Augensekretion or redness and changes in vision. In addition to vision loss and pain flashes and Rußregen are (both can be symptoms of a retinal detachment), diplopia and visual field defects troubling symptoms. Physical examination visual acuity The first step is the determination of the visual acuity (visual acuity). Many patients do not exert themselves to intervene appropriately. Therefore, you should in the visual acuity for sufficient time and motivate the patient to achieve reliable results as possible. Visual acuity is determined with and without glasses. If the patients have their glasses do not turn a stenopaic panel is used. If no pinhole is available, the investigation at the bedside can also use different sized holes (z. B. with an 18G needle) may be carried out in a piece of cardboard. The patient chooses the hole that best corrected visual acuity his. If the visual acuity can be corrected by such a hole, there is a refractive error. This test is a fast and efficient way to diagnose refractive errors, the most common cause of impaired vision. As a rule, however, only a visual acuity of 20/30 and not of 20/20 can be achieved with the pinhole. In the visual acuity the other eye is covered with an opaque object (not with the patient’s fingers as they can diverge during the test). The patient then looks at a test panel in about 6 m. (Editor’s note: In Germany, the standard test distance is 5 m!) If this test is not possible, the visual acuity can be determined from a corresponding table that is held at a distance of about 36 cm from the eye. The normal visual acuity and deviations shall be quantified Snellen. In the Snellen eye test an indication of 20/40 (6/12 metric) means that the smallest character that can read a person with normal in 40 feet (12 m) distance, to 20 feet (6 m) must be approximated in order the patient may recognize it (translator’s note .: In Germany, the visual acuity is quantified with Landolt rings as optotype;.., an eye can Healthy under standard conditions of 2.0 reach a Visuswert). For the patient, the smallest line in which he can identify half of the letter is indicated, even if it itself has the feeling that they have not seen this true or is blurred. If the patient is unable to read the top line of Snellen panel at 6 m, the visual acuity is tested at 3 m. If nothing is detected on the panel also able to finish, the auditor holds a different number of fingers in front of the patient to see if he can see them. If he can not see them, it is checked whether the patient recognizes hand movements. If that does not succeed, a light is directed into the eye to examine whether it is perceived. To check the near vision to the patient a standard reading chart or magazine is presented in 36 cm distance. Patients> 40 years should put on their reading glasses during Nahvisusprüfung. Based on the lens power needed by the investigator to focus the retina with a direct ophthalmoscope, to refractive error can be roughly estimate. For this, the investigator may need to be put on his own glasses. However, the process can never replace the comprehensive refraction. Frequent refractive be a phoropter or a refractometer determined automatically (a device that changes the projected into the eye and may measure from this reflected light). These devices also astigmatism can be measured (overview of refractive errors) .Untersuchung the lids and the conjunctiva Examination of the eyelid margins and periocular tissue is under focal illumination with magnification (z. B. with a magnifying glass, slit lamp or einemOphthalmoskop). Suspicion of Dakryozystitis or canaliculitis the lacrimal sac is palpated and attempts to express the contents through the canaliculi and lacrimal punctum. The lids are everted to (conjunctival fornices) the conjunctiva of the eyelids, of the eyeball and the transition wrinkles on foreign matter, signs of inflammation (e.g., B. follicular hypertrophy, exudate, hyperemia, edema) or other changes towards untersuchen.Hornhautuntersuchung Blurred or blurred edges of the corneal light reflex (light reflection upon illumination of the cornea) suggest that the corneal surface is not intact or roughened as it is observed in a corneal erosion or keratitis. Using a fluorescein staining can be revealed erosions and ulcers. If the patient has pain or needs when the cornea or conjunctiva be touched (for. Example, for removing a foreign body or for the measurement of intraocular pressure), a instillierter prior to staining drops of a local anesthetic can (z. B. proparacaine 0.5% or tetracaine 0.5%) facilitate the study. A sterile, individually packaged fluorescein-strip is wetted with 1 drop of sterile saline solution or a local anesthetic and then – placed on the inside of the lower lid for a short time – by upwardly directed view of the patient. Thus, the dye in the tear film spread, the patient should blink several times. After that, the eye is examined under magnification and cobalt blue filter light. Areas where the corneal or conjunctival epithelium missing (abraded or ulcerated), fluoresce grün.Pupillenuntersuchung size and shape of the pupils are noted. To test the light response of each eye is first illuminated separately in view of the patient into the distance. With a flashlight the swinging-flashlight test is then performed to examine the direct and consensual light reaction. This consists of three steps: A pupil is maximum narrowed by s illuminate the eye for 1-3 with the lamp. Then the flashlight on also is 1-3 s rapidly moved to the other eye. Then the lamp is moved back to the first eye again. Normally the pupil reacts to direct light (direct pupillary response) as well as with indirect when the light falls on the other eye (consensual light reaction). However, if the perception of light in an eye, for example due to a disturbance is afferent (from the optic nerve to the optic chiasm) or serious retinal disease, disturbed, then the consensual light reaction in the affected eye is stronger than the direct reaction. Thus, it may be a dilation of the pupil of the affected eye in the third step of the test, paradoxically, when it is illuminated again. This finding points to a so-called. Relative afferent pupillary defect out (RAPD or Marcus Gunn pupil) .Äußere eye muscles The patient follows with his eyes finger or penlight of the examiner in the 8 viewing directions (up, up-right, right, right dOWN ARROWS, down, down-left, left and left-above). The doctor pays attention to deviations of the eyes, movement restrictions, a dyskonjugierten view or a combination of these symptoms as indicating a cranial nerve palsy, a Orbitakrankheit or other abnormality that einschränkt.Ophthalmoskopie eye movement A ophthalmoscopy (examination of the posterior segment of the eye) can carried out directly using an ophthalmoscope held by the hand or with a hand-held lens in conjunction with the slit lamp biomicroscope. An indirect ophthalmoscopy can be performed with a head-mounted ophthalmoscope with a hand-held magnifying glass. The direct ophthalmoscope is initially set by the examiner at a knurled to 0 diopters and the dioptric power increases with the knurled screw thereafter as long or reduced until the fundus is in focus. With the direct ophthalmoscopy only a small retinal cutout can be represented, while the indirect ophthalmoscope gives a three-dimensional image and a better overview of the peripheral retina allows where retinal detachments occur most often. The view of the fundus can be improved by dilation of the pupils. In front of a dilatation-drug, the depth of the anterior chamber is estimated because a mydriasis in a flat anterior chamber may cause an acute angle closure glaucoma. This can be done by using a slit lamp or less accurate with a flashlight, which is held at the temporal limbus parallel to the plane of the iris in the direction of the nose. If the media iris while in the shade, the chamber is flat, and there should be no drug pupil dilation. Other contraindications to mydriasis, a head trauma, a suspicion of globe rupture, a close chamber angle or narrow-angle glaucoma. For pupil dilation 1 drop tropicamide is 1%, 2.5% phenylephrine or both given (possibly repetition after 5-10 min). If a longer duration of action desired or should fail dilation more, 1% can be used instead of the Tropicamids cyclopentolate. With the ophthalmoscopy lens or vitreous opacities can be discovered, evaluated the optic cup (Cup / disc ratio) and retinal and vascular changes are identified. The optic cup is the central depression and the optic nerve head, the entire surface of the exiting optic nerve. The normal ratio of the excavation to nerve diameter is 0-0.4. A ratio ? 0.5 can mean the loss of ganglion cells and be a sign of glaucoma. Retinal changes include hemorrhage, manifested as small or large areas of blood drusen (small, subretinal yellowish-white spots, which can be an indication of an age-related dry macular degeneration). Vascular changes include Arteriovenous cutting, a sign of chronic hypertension, in which the retinal veins are compressed by artery at the point where both cross each copper wiring, a sign of atherosclerosis, wherein the thickened Arteriolenwände increase the thickness of the specular silver wiring, a sign of hypertension, reduce the thickness of the light reflection at the thin, fibrotic arteriolar walls loss of venous pulsations, a sign of increased intracranial pressure in patients of which is known to have had pulsations. Slit lamp examination The slit lamp focused height and width of a light gap. The investigation produced a precise stereoscopic image of eyelid, conjunctiva, cornea, anterior chamber, iris, lens and anterior vitreous. With a condenser handset, it can also be used for a detailed examination of the retina and macula. There are for the following applications: identification of foreign bodies and abrasions of the cornea determining the depth of the anterior chamber detection of cells (erythrocytes or leukocytes) and flare (protein detection) in the anterior chamber identification of a Skleraödems that is recognizable as a protrusion of the gap forward when the slit lamp is focused under the conjunctiva; usually indicate a scleritis identifying diseases such as macular degeneration, diabetic eye disease, preretinal membranes, macular edema, and retinal tears (when using a converging lens) tonometry and gonioscopy (for the quantification of the chamber angle with special lenses) .Perimetrie The visual field can be obtained by lesions somewhere in the course of Sehbahn be limited by the optic nerve to the occipital lobe (s visual field defects and higher visual pathways -. lesion and corresponding visual field defects.). Glaucoma results in the peripheral visual field defects. The field can roughly with the direct confrontation technique or more accurately assessed by a study on apparatus. In direct confrontation of the patient focuses on one eye or the nose of the examiner. The examiner performs a small target object (for. Example, a match or a finger) slowly from the periphery in each of the 4 quadrants of the visual field of the patient and allows him to specify in each case, from when he perceives the object. A slight shake of the object helps the patients in the exercise. In another form of direct confrontation art, some fingers are presented in each quadrant. The patient indicates how many fingers he can see. In both forms, the eyes are examined separately. Anomalies in the investigation of the confrontation technique should immediately lead to a more accurate apparatus visual field examination. Exact method of the tangent board, the Goldmann Perimetry or threshold perimetry are (the computer calculates the visual field on the basis of reactions of the patient to light flashes which are computer controlled projected to different positions). With the Amsler grid, the central visual field is examined. A distorted perception of the grid (metamorphopsia) or a missing area (central scotoma) can talk (z. B. choroidal neovascularization, CNV), such as in age-related macular degeneration of a disease of the macula. Visual field defects Type * Description Causes altitudinal visual field defect Partial or total failure of the upper or lower half of the visual field without crossing the horizontal median Common: ischemic optic neuropathy, partial retinal artery occlusion, retinal detachment Rare: glaucoma, optic nerve or Chiasmaläsion, Sehnervkolobom Scalloped visual field defect Little arcuate visual field defect, following the arcuate pattern of the retinal nerve fibers; not cross the horizontal median ganglion cell damage in a specific optic nerve section Common: glaucoma Rare: ischemic optic neuropathy (usually not arteritic) Papillendrusen, high myopia Binasaler visual field defect (rare) Partial or total failure of the medial visual field without crossing the vertical median Common: glaucoma, bitemporal retinal diseases (. e.g., retinitis pigmentosa) rare: bilateral Okzipitalläsion, tumor or aneurysm compress both optic nerves Bitemporal hemianopia partial or total failure of the lateral fields of view without crossing the vertical median Common: Chiasmaläsion (eg. B. pituitary adenoma, meningioma, craniopharyngioma, aneurysm, glioma) Less common: a tilted optic disc Rare: Nasal retinitis pigmentosa Enlarged blind spot extension of the normal blind spot at the optic nerve papilledema, Papillendrusen, Sehnervkolobom, myelinated nerve fibers of the optic nerve, medications, myopic papilla with Conus myopic vision in the central scotoma loss of the center of the field macular disease, optic neuropathy (z. B. ischemic or congenital Leber’s hereditary optic neuropathy, neuritis n. optici in multiple sclerosis) (, optic atrophy z. B. tumor by compression of the nerve or toxi sch-metabolic disorders) Rare: injury of the occipital lobe tunnel-like restriction of the peripheral visual field except for a small central area loss of the outer parts of the entire field of vision in one or both eyes of glaucoma, retinitis pigmentosa, or other peripheral retinal disorder, chronic choked by panretinal photocoagulation, retinal central retinal artery occlusion with the recess A. cilioretinalis, bilateral Okzipitalinfarkt receipt of macular vision, non-physiological vision loss, cancer-associated retinopathy rare: drugs homonyms hemianopia Partial or total failure of the left or right visual field without Queru ng of the vertical median lesion of the optic tract or the lateral lateral geniculate body; Lesion in the temporal, parietal, or occipital lobe (often by stroke or tumor, more rarely by aneurysm or trauma); Migraine (possibly with temporary homonymous hemianopia) * A migraine can cause various visual field defects, but most often it comes to homonymous hemianopia. After Rhee DJ, Pyfer MF: The Wills Eye Manual, 3rd ed Philadelphia. Lippincott Williams & Wilkins, 1999 examination of the color sense to check the color sense 12-24 Ishihara color plates are often used on which colored numbers or symbols in a field of colored dots. Color-blind patients or patients with acquired color vision deficiency (z. B. in Optikuskrankheiten) may not recognize all the hidden numbers. The most common congenital color vision disorder is a red-green color anomaly, the most common acquired (z. B. in glaucoma or Optikuskrankheiten) is a blue-yellow anomaly. Tests tonometry When tonometry intraocular pressure over the force is measured which is required to applanate the cornea. For screening, portable pen-like tonometer can be used. For this purpose, a local anesthetic is required (eg. B. Proparakain 0.5%). Another hand tonometer, the iCare tonometer can be used without local anesthesia. The iCare tonometer is useful in children and is widely used in emergency rooms of non-ophthalmologists ( “nonophthalmologists”) is used. With a permanently mounted noncontact tonometer (air pulse tonometry) a screening is also possible in practice; it requires less exercise, since no direct corneal contact occurs. Goldmann (applanation) tonometry is the most accurate method, but requires practice and is usually done only by an ophthalmologist. The measurement of the intraocular pressure alone is not adequate glaucoma screening. It should also of the optic nerve werden.Angiographie examines the fluorescein is for screening hypoperfusion and used by neovascularization secondary to diseases such as diabetes mellitus, age-related macular degeneration, retinal vascular occlusion, and ocular inflammation. It is also useful for preoperative diagnostic assessment before a retinal laser photocoagulation. After the i.v. injection of fluorescein retinal, choroidal, papillary or iris vessels are photographed in rapid succession. ICG angiography is used to represent the retinal and choroidal vessels and can sometimes provide a more accurate assessment of the choroidal vasculature as fluorescein angiography. It is used in age-related macular degeneration and can be especially helpful in the detection of neovascularization. (Editor’s note: is now rarely used in AMD!) Optical coherence tomography Optical coherence tomography (OCT) provides high-resolution images of the posterior structures of the eye such as the retina (including retinal pigment epithelium), the choroid and the posterior vitreous. Also retinal edema can be detected in this way. The OCT operates in a similar manner as sonography, but uses light instead of sound; Contrast agents are also not required; There is also no ionizing radiation and is noninvasive. OCT is useful for imaging retinal diseases that cause macular edema or fibrous proliferation over or under the macula, including age-related macular degeneration, diabetic edema, macular hole and epiretinal membranes. It is also useful to the progression of glaucoma at überwachen.Elektroretinographie with electrodes which are placed on both corneas and surrounding skin, the electrical activity of the retina is recorded. With this technique, the retinal function in patients can be determined with retinal degeneration. A determination of the vision here is about not möglich.Sonographie The B-mode ultrasonography provides even in corneal and lens opacities two-dimensional structural information. Examples of its application in ophthalmology: examination of retinal tumors -ablösung or vitreous hemorrhage, localization of foreign bodies, representation of a posterior Skleraödems posterior scleritis as a mark of distinction and uveal melanoma from a metastasis or subretinal hemorrhage. The one-dimensional A-scan ultrasonography is used to determine the axial length of the eye. This measurement is necessary prior to the implantation of an intraocular lens in a cataract operation to calculate their strength. In the ultrasound pachymetry corneal thickness with ultrasound determined (z. B. before a refraktivchirurgischen engagement, such as the Lasik, short LASIK, or corneal dystrophies) .CT and MRI will These imaging methods are most common in eye injuries , used in particular in a suspected intraocular foreign bodies, as well as for the study of orbital tumors, optic neuritis and Optikustumoren. If you suspect a metallic foreign body no MRI should be performed werden.Elektronystagmographie clarification of ear diseases: Tests.

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